Metallurgical furnace



July 3l, 1928'. F. s. Mcku'NE IIETALLURGICAL FURNACE med lay 5, 1922 July 31, 1928. F. a. MCKUNE METALLURGIGAL FURNACE Filed nay 5,'1922 4 Sheets-Sheet 2 JMUQIZOI www@ July 3l, i928. F' .B ""KUNE METALLURGICAL FURNACE 4 Sheets-She 3 r'nea lay 5. 1922 et July 3l, 1928. -F. a. McKuNg METALLURGICL FURNACE 4{Sheets-Sheet 4 Filled lay 5, 1922 4 40 forced air to t e furnace.

` y Paieafed July 31, 1928.I

l iJNlrED STATES PATENT OFFICE.

FRANK B. maxima, or HAMILTON, ONTARIO, CANADA, AssIGNon, BY ims'NE ASSIGN- MENTS, To OPEN HnAn'rH COMBUSTION COMPANY, or CHICAGO, ILLINOIS, A Con- IPORATION OF DELAWARE.

METALLURGICAL FURNAUE.

Application led Hay 5, 1922. 'Serial No. `558,756.

, This invention relates to a new and iinproved metallurgical furnace and more par- `ticularly to a' reversible open hearth furnace.

Open-hearth furnaces, as generally con-V 5 structed, are double ended, and being reversed in operation, the ports and passages I at the ends serve alternately to introduce fuel and air and to Carry oif the products of f combustion. The products of Acombustion considerably exceed in volume the incoming -air and fuel and the ports and passages are,

. therefore, of necessity largely designed with a view of taking Acare of the products of combustion. Consequently, these passages are not ordinarily of la size and shape best adapted for the proper introduction of the fuel and air. They do not thus so introduce the fuel and air as to adequately mix the air with the fuel .and produce an efficient flame. 2Moreover, they donot properly direct and control the llame produced.

May 11, 1920, I have disclosed a furnace construction adapted to obviate these diiiiculties. In lthiswconstruction I have provided Asupplemental ports and passages ada ted to serve to aid in carrying olf the pro ucts of combustion, and have provided means whereby the supplemental passages may beV controlled and their eiectvexarea changed. The construction shown in the present application is a modification of that of my prior patent, and shows improvements of certain detailed arrangements, although in itsy broader aspects the -invention of this application is shown but not claimed in my prior patent above mentioned.

In the prior-patent, I have disclosed a construction havin means adapted to supply In the present application .I have shown fans and passages particularly adapted for supplying forced air to a furnace of similar construction.

It is an object of the present invention to 4fprovide a furnace'and appurtenances adapt' ed to utilize forced air upon the incom# ing end of the furnace through a relatively restricted opening and upon the outgoing end of the furnace to afford a relatively` large port area whereby to carry oif the products ofcombustion.

' It isa further object to provide a furnace of thisI type which is simple in ydesign and which may be applied to existing installa- Inl my prior Patent No. 1,339,855, issuedtions without much material alteration therein. Other and further objects will appear as the description proceeds.

ist

While I am aware that fans have been used l in some prior installations for the purpose of forcing the incoming air throughv the brickwork in the checker chamber and supk plying it to the furnace, it has been impractical to'actuallyfuse air which enters the furnace. at any considerable .pressure since 1n these prior constructions, the passages for the products of combustion lwere onlyequal inarea to the incoming passages and would fail to. carry OE a quantity of air such as would be introduced if the air were forced. In such constructions, consequently a positive Apressure would be created in the furnace chamberfi'f forced air `were used, and iiames would tend to pass out through all openings. Such a method ofl Operation is impractical and would be destructive to the furnace.4

Under my construction, where the area for the products of combustion is considerably greater than that for the incoming air and fuel, the air can be forced in under pressure and thus give a flame of the blow pipe type which may be adequately con- Figure 2;

Figure 4 is a vertical section on an enlardged scale showing one end of the furnace; an

Figure 5 .is' a Ahorizontal section taken on line 5;-5 of Figure 4.

Referring 'in particular tov Figure 1, the furnace chamber 8 is connected through air and fuel port 9 and uptake 10 with slagd pocket 11. It is also connected with this slag pocket 10 through the large port 1,2 and the lateral uptakes 13. The wall 14 divides ico the slag pocket 11 from the checker chamber 15, communication existing through the passage 16. The checker chamber is connected through passages 17 and 22 with the stack 18, the passage 22 being controlled by valve 19.

Referring now to Figure 2, two checker chambers 15 and 15 are provided at one end of the furnace and checker chambers 20 and 20 at the opposite end of the furnace. The checker chamber 15 communicates through passage 17 with the passage 22, the lat-ter connecting the passage 17 with the stack. The checker chamber 15 is connected by-passage 23 with the passage 17 and the passage 17 is controlled by valve 24 between the junction of passage 23 with passage 17 and that Aof passage 17 with passage 22. The checker chamber 20 is connected by passage 25 with the passage 22 and the checker chamber 20 is connected by passage 26 with passage 25. The valve 27 is located in passage 25 between the junction of such passage with passage 26 and with passage 22 The forced air main 28 leads from the blowers or fans 29 and 30 and they split into branches 31 leading to passage 17, and 32 leading to passage 25. These two branches 31 and 32 are controlled by valves 33 and 34 at their points of junction with passages 17 and 25. The valve 35 is located in the air main 28 between the two blowers 29 and 30.

Referring now to Figures 4 and 5, the fuel pipes 36 lead laterally into the inlet port 9 and discharge in a trench 37 extending across such port. As shown in Figure 4, the outer end of the port 9 is protected by the water-cooled pipes 38 and the turn from the uptake 10 to port 9 is similarly protected by pipes 39. As` shown in this figure, there is a slag pocket 11 which communicates with the slag pocket 11 through opening 40. It will be understood that slag pocket 11 connects with regenerator or checker chamber 15.

The lateral uptakes 13 are controlled by dampers 41 which move on water-cooled guideways 42. These dampers 41 are connected by links 43 with arms 44-which arms are rigidly connected to rock shaft 45. As best shown in Figure 4, the shaft 45 is provided with-the toothed wheel 46. Cooperating with this wheel 46 .-,are' the racks 47 and 48 which are connected to plungers extending into the cylinders 49 and 50. These cylinders are connected to valve 51 by means of pipes 52 and 53 respectively.

In the operation of my furnace, eitherv fans 29 or 30 or both will be operated to supply forced air to the-main 28. When the furnace end connected with regenerator chambers 15 and l5 is used as the incoming end, the valve 24 will be closed, blocking off passages 17 and 23 from the passage 22. The valve 34 will be closed, blocking off the air main from the passages 25 and 26. The valve 33 will be open and the forced air will enter both passages 17 and 23 and pass through checker chambers 15 and 15l to sla;r pockets 11 and 11. The air will be heated in the checker chambers and the air from slag pocket 11 will join that in slag pocket ll through the opening 40. On this end of the furnace, the danipers 41 are upon their inner positions and blank off the uptakes 13. The air thus can only go through the uptake 10 and will pass up this uptake and thence through the port 9 to the furnace chamber 8. At the same time, the fuel gas is introduced through pipes 36 and mingles with the air in the port 9 so that a proper mixture is had and an adequate flame is directed from the port on to the metal bath in the furnace chamber.

lt is to be understood, of course, that the construction upon the opposite end of the furnace is identical with that upon the ends shown. Upon this opposite end, the dampers 41 are withdrawn, and the uptakes'l are thus clear. This movement of the dampers is accomplished by introducing air through pipe 53 into cylinder 50 forcing down the rack 48. This rack coacts with wheel 46 to rotate shaft 45 and through arm 44 and link 43 to draw out the dampers. It will be' understood that as ,the wheel 46 rotates, the rack 47 will be forced u wardly andair from cylinder 49 will e permitted to pass out through pipe 52.

Upon the outgoing end, the products of combustion will pass through the large port 12 to the uptakes 13 and thence to the slag pocket. The will also pass through port 9 down upta re 10 to the slag pocket. From the slag pockets they will pass to regenerative chambers 2O and 20 and through passages 25 and 26 to passage 22 and thence to stack 18. When the furnace is reversed, the dampers will be reversed in their positions upon the opposite ends. The valve 33 will then be closed and valve, 34 open to direct the incoming air to the passages 25 and 26. the valve 27 being closed to prevent the air reaching the stack. The valve 24 will b e opened to permit the products of combustion to reach the stack through passage 22.

While I have described the operation thus far as having the dampers fully closed upon one end and fully opened upon the other, it is obvious that upon the incoming end, the dampers may be partially opened in order to introduce secondary air through the large port 12. This may be desirable under certain circumstances, such, for example, as to protect the roof when melting down large amounts of scrap in the furnace, as the scrap tends to break up the flame `and throw it against the roof and Walls.. The dampers may be' adjusted to varying positions to permit varying amounts of secondary air under different conditions.

In the construction shown, the furnace is adapted for the use of natural or coke oven gas or liquid fuels. IVith such fuels the installation may be simplified by eliminating one of the checker chambers and the corresponding slag pockets and passages, upon each end of the furnace. The double set of chambers is required for use in preheat-ing the fuel gas When-producer or similar gas is used;

lVhile the particular construction shown has been found particularly efficient in the use of forced air, it is illustrative only of my invention, and I reserve the right to make such modifications and changes in the construction to meet varying conditions, as come Within the scope of the appended claims.

I claim:

1. In combination with a reversible metallurgical furnace, air entrance passages, movable means yvhereby the entrance area for incoming air to the furnace chamber may be restricted, and fans for supplying forced air to said passages.

2. In combination With a reversible furnace, air entrance passages, discharge passages for the products of combustion, said entrance passages being of less effective area than the discharge passages at their point of connection with the furnace chamber, and fans for supplying forced air to said entrance passages.

3. In combination with a reversible furnace, air passages, a restricted ort and a larger port associated with sait passages, means for changing the effective combined area of said ports, and means for supply.- ing forced air to said passages.

4. In combination with areversible furnace, air passages, a restricted port and a larger port associated with said passages, means for changing the effected area of said larger port, and means for supplying forced air tofk said passages.

5. In combination with a reversible furnace, air passages, a restricted portand a larger port associated With said passages, means for changing the combined effective area of said ports, and means for supplying forced air to said passages, both said ports serving on the outgoing end to carry off products of combustion.

6. In combination with a reversible furnace, air passages, a restricted port and a larger port associated With said passages, means for changing the effective area of the larger port While maintaining the restricted port constant, and means for supplying forced air to said passages.

'7. In combination with a reversible fur'- nace, air passages, a restricted port and a` plying forced air to said passages, both said ports serving on the outgoing end to carry off products of combustion.

Signed atl Hamilton, Ontario, this 21st day of April, 1922. :j

FRANK B. LICKUNE. 

